Each of Chinese patent applications 201210171681.9 and 201210088237.0 discloses a micro chamber processing apparatus for processing a semiconductor wafer. The micro chamber processing apparatus includes an upper chamber portion and a lower chamber portion. Driven by a driving device, the upper and lower chamber portions may relatively move between an open position for loading and/or unloading the semiconductor wafer, and a closed position for accommodating and processing the semiconductor wafer. A micro chamber is formed when the upper and lower chamber portions are disposed in the closed position, and the semiconductor wafer is placed in the micro chamber. Either or both of the upper and lower chamber portions may include one or more inlets, via which processing fluid may enter the micro chamber, and one or more outlets, via which the processing fluid may exit the micro chamber.
The upper chamber portion has a horizontal surface, referred to as an upper working surface, that faces the micro chamber. The lower chamber portion also has a horizontal surface, referred to as a lower working surface, that faces the micro chamber. It is difficult to control the processing fluid when the processing fluid enters the micro chamber via the one or more inlets, and the processing fluid may flow in random directions. Moreover, the micro chamber processing apparatus needs a rather large quantity of the processing fluid, which makes detecting a low-level chemical at a surface of the semiconductor wafer an extremely difficult task. That is, the chemical would dissolve in the rather large quantity of the processing fluid, and the density of the chemical would become very low and thus extremely difficult to detect.